Thyrotropin- and Gonadotropin-Secreting Pituitary Adenomas
Pituitary tumors that secrete growth hormone (GH), ACTH, and prolactin have been well characterized and result in distinct clinical syndromes. In contast, pituitary adenomas that secrete thyroid-stimulating hormone (TSH) or gonadotropins [follicle-stimulating hormone (FSH) and luteinizing hormone (LH)] are infrequent in clinical practice and consequently less well appreciated by clinicians managing patients with pituitary disorders. Caughey1 drew attention to the fact that prolonged deprivation of the negative-feedback hormone secreted by the target organ can lead to hyperplasia and subsequently adenomatous transformation of the appropriate tropic-hormone-secreting adenohypophyseal cell. More recently, it has been recognized that primary tumors of the pituitary occur that secrete TSH or gonadotropins without prior thyroidal or gonadal failure. Further, it appears that pituitary adenomas may, on occasion, secrete peptides similar to, but not identical with, the authentic hormone, for although immunoreactivity is recognized by radioimmunoassay, the molecular species is not biologically active. Such circumstances may apply to all pituitary tumors including those that produce TSH and gonadotropins.
KeywordsThyroid Hormone Luteinizing Hormone Pituitary Adenoma Pituitary Tumor Primary Hypothyroidism
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- 2.B. Niépce, Traite due goitre et du crétinisme, suivi de la statistique des goitreux et des crétins dans le basin del’Isere en Savoie, dans les departements de l’Isere, des Hautes-Alpes et de Basses-Alpes, Balliere, Paris, 1851.Google Scholar
- 34.L. Axelrod, R.M. Neer, and B. Kliman, Hypogonadism in a male with immunologically active, biologically inactive luteinizing hormone: An exception to a venerable rule, Clin. Res. 26:610A, 1978.Google Scholar
- 38.R. Luboshitzky and D. Barzilai, Suprasellar extension of tumour associated with increased cerebrospinal fluid activity of LH and FSH, Acta Endocrinol. (Copenhagen) 87:673, 1978.Google Scholar